But the Transport secretary and his junior ministers were unavailable to defend the rises.

Downing Street confirms that Grayling has embarked on a previously unannounced trip to the Middle East.

LONDON – The Transport Secretary Chris Grayling has been accused of going into “hiding” after a spokesperson for the prime minister confirmed he had embarked on a trip to Qatar at exactly the same time as train fairs rose above inflation across the country.

Train fares rose by an average of 3.4% across the country this morning as commuters returned to work after the new year.

However, questions were raised with Downing Street after neither Grayling or any other Transport minister appeared on broadcast interviews this morning to defend the rises.

A spokesperson for the prime minister said that Grayling would be meeting with the prime minister of Qatar and industry figures.

Asked about the timing of Grayling’s trip at a briefing with journalists on Tuesday morning, they replied: “The fare rises we have known were coming for a while and the Department for Transport has issued a full statement responding to those rises.”

Grayling is not expected to return to the UK until the end of the working week, days after passengers were first hit by the rises.

McDonald’s own day of campaigning on the issue of nationalised trains was brought to a halt today due to a broken down train.

My day of campaigning has been interrupted by a broken down train on the recently bailed-out Virgin East Coast on the same day fares are hiked by 3.6%. Let’s take our railway back into public ownership! pic.twitter.com/Y6YrK0iTMT

“Rail passengers are shivering on platforms angered by the biggest fare increase in years while Chris Grayling is off globetrotting,” he tweeted.

“It’s very difficult to see what useful function he can perform in Qatar and Turkey that our excellent trade officials could not.”

One leading transport union said passengers would “draw their own conclusions” about Grayling’s absence.

“Chris Grayling knew that the fares story would be top of the news agenda today but instead of being available to defend his Governments great rail rip-off he booked himself a winter escape to the Qatari sunshine,” RMT General Secretary Mick Cash said. “While millions of passengers are taking a financial hit as they battle their way back to work in the cold and the rain‎ today they will draw their own conclusions from the Transport Secretaries decision to book himself a trip to the desert rather than face the music.”

Grayling’s job is reportedly under threat in the prime minister’s upcoming reshuffle. Grayling also faced calls last week to quit from the former National Infrastructure Commission chief Lord Adonis, over his role in the bailout of Stagecoach-Virgin run East Coast line.

Asked about his position, a spokesperson for the PM said that: “Chris Grayling is working hard and doing a good job as transport secretary.”